离子漏斗聚焦光电离质谱仪的研制及其在大气苯系物在线监测中的应用  

Development of Ion Funnel Focusing Photoionization Mass Spectrometry and Its Application in Online Monitoring of Atmospheric Benzene Series

作　　者：李函蔚 蒋吉春 杨明 樊志刚 张栢茂 田地[1] 花磊[2] 李海洋[2] LI Han-Wei;JIANG Ji-Chun;YANG Ming;FAN Zhi-Gang;ZHANG Bai-Mao;TIAN Di;HUA Lei;LI Hai-Yang(College of Instrumentation&Electrical Engineering,Jilin University,Changchun 130061,China;CAS Key Laboratory of Separation Science for Analytical Chemistry,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Environmental and Chemical Engineering,Dalian University,Dalian 116023,China)

机构地区：[1]吉林大学仪器科学与电气工程学院,长春130061 [2]中国科学院大连化学物理研究所,中国科学院分离分析化学重点实验室,大连116023 [3]中国科学院大学,北京100049 [4]大连大学环境与化学工程学院,大连116023

出　　处：《分析化学》2022年第10期1456-1464,共9页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.22027804,22174142);大连化学物理研究所创新研究基金(Nos.DICP I202144,DICP I202123)资助。

摘　　要：大气苯系物具有较高的光化学反应活性和生物毒性,是最重要的大气挥发性有机污染物之一,然而其浓度低,时空变化快,对其进行实时准确的定量监测极具挑战。真空紫外光电离(VUV-PI)质谱技术是苯系物在线监测常用的分析方法,但目前常用的VUV-PI电离源无法有效利用源内产生的离子,制约了灵敏度的进一步提升。本研究设计了一台新型离子漏斗聚焦光电离源-飞行时间质谱仪(IFPI-TOFMS),通过在电离源内引入射频离子漏斗聚焦技术,将源内离子传输效率提升了26~37倍,在5 s内,对异戊二烯、苯、甲苯、苯乙烯、对二甲苯、三甲苯和柠檬烯7种化合物的检出限(LODs)分别达到34.3×10^(-12)、7.9×10^(-12)、7.0×10^(-12)、9.4×10^(-12)、7.7×10^(-12)、10.6×10^(-12)和13.7×10^(-12)(V/V),并且具有2~3个量级的线性范围,线性相关系数(R2)均大于0.99。IFPI-TOFMS具有较好的稳定性,12 h连续监测的相对标准偏差(RSD)小于3%。利用所设计的IFPI-TOFMS对大连市区大气苯系物进行在线监测,结果表明,IFPI-TOFMS可在5 s内实现大气中10^(-12)(V/V)量级苯系物的高灵敏度实时在线定量监测,在大气环境监测领域具有潜在的应用价值和广阔的发展前景。Atmospheric benzene series have high photochemical reactivity and biological toxicity,and have been one of the most important atmospheric volatile organic pollutants.However,their low concentration and rapid temporal and spatial changes make real-time and accurate quantitative monitoring extremely challenging.Vacuum ultraviolet photoionization(VUV-PI)mass spectrometry is a commonly used analytical method for online monitoring of benzene series,but the currently commonly used VUV-PI ionization source cannot effectively utilize the generated ions,which restricts the further improvement of sensitivity.In this study,a novel ion funnel focused photoionization time-of-flight mass spectrometer(IFPI-TOFMS)was developed.By introducing a radio frequency ion funnel into the photoionization source,the ion transmission efficiency in the source was increased by 26-37 times,and the limits of detection(LODs)of IFPI-TOFMS for isoprene,benzene,toluene,styrene,p-xylene,trimethylbenzene,and limonene reached 34.3×10^(-12),7.9×10^(-12),7.0×10^(-12),9.4×10^(-12),7.7×10^(-12),10.6×10^(-12)and 13.7×10^(-12)(V/V)within 5 s,respectively.Linear range of 2-3 orders of magnitude were achieved with the linear correlation coefficients(R2)greater than 0.99.The relative standard deviation(RSD)during 12 h monitoring was less than 3%,which exhibited good stability of IFPI-TOFMS.IFPI-TOFMS was utilized to carry out real-time online monitoring of atmospheric benzene series in Dalian urban area.The results showed that benzene series in the atmosphere down to 10^(-12)(V/V)could be quantitatively monitored in real-time and online by IFPI-TOFMS,which indicated that IFPITOFMS had potential application value and broad development prospects in the field of atmospheric environment monitoring.

关 键 词：光电离 飞行时间质谱 离子漏斗 大气苯系物 在线监测 

分 类 号：X831[环境科学与工程—环境工程] O657.63[理学—分析化学] TH843[理学—化学]